Formation Mechanisms of Electrical Conductivity and Optical Properties of ZnO:N Film Produced by Annealing Treatment
WANG Xiang-Hu1,2, YAO Bin1, WEI Zhi-Peng1, SHEN De-Zhen1, ZHANG Zhen-Zhong1, LU You-Ming1, ZHANG Ji-Ying1, FAN Xi-Wu1
1Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 1300332Shanghai Dianji University, Shanghai 200240
Formation Mechanisms of Electrical Conductivity and Optical Properties of ZnO:N Film Produced by Annealing Treatment
WANG Xiang-Hu1,2, YAO Bin1, WEI Zhi-Peng1, SHEN De-Zhen1, ZHANG Zhen-Zhong1, LU You-Ming1, ZHANG Ji-Ying1, FAN Xi-Wu1
1Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 1300332Shanghai Dianji University, Shanghai 200240
The effects of annealing on the chemical states of N dopant, electrical, and optical properties of N-doped ZnO film grown by molecular beam epitaxy (MBE) are investigated. Both the as-grown ZnO:N film and the film annealed in N2 are of n-type conductivity, whereas the conductivity converts into p-type conductivity for the film annealed in O2. We suggest that the transformation of conductivity is ascribed to the change in ratio of the N molecular number on O site (N2)O to the N atom number on O site (NO) in ZnO:N films under the various annealed atmosphere. For the ZnO:N film annealed in N2, the percentage content of (N2)O is larger than that of NO, i.e.the ratio >1, resulting in the n-type conductivity. However, in the case of the ZnO:N film annealed in O2, the percentage content of (N2)O is fewer than that of NO, i.e., the ratio <1, giving rise to the p-type conductivity. There is an obvious difference between low-temperature (80K) PL spectra of ZnO:N film annealed in N2 and that of ZnO:N film annealed in O2. An emission band located at 3.358eV is observed in the spectra of the ZnO:N film after annealed in N2, this emission band is due to donor-bound exciton (D0X). After annealed in O2, the PL of the donor-bound exciton disappeared, an emission band located at 3.348eV is observed, this emission band is assigned to acceptor-bound exciton (A0X).
The effects of annealing on the chemical states of N dopant, electrical, and optical properties of N-doped ZnO film grown by molecular beam epitaxy (MBE) are investigated. Both the as-grown ZnO:N film and the film annealed in N2 are of n-type conductivity, whereas the conductivity converts into p-type conductivity for the film annealed in O2. We suggest that the transformation of conductivity is ascribed to the change in ratio of the N molecular number on O site (N2)O to the N atom number on O site (NO) in ZnO:N films under the various annealed atmosphere. For the ZnO:N film annealed in N2, the percentage content of (N2)O is larger than that of NO, i.e.the ratio >1, resulting in the n-type conductivity. However, in the case of the ZnO:N film annealed in O2, the percentage content of (N2)O is fewer than that of NO, i.e., the ratio <1, giving rise to the p-type conductivity. There is an obvious difference between low-temperature (80K) PL spectra of ZnO:N film annealed in N2 and that of ZnO:N film annealed in O2. An emission band located at 3.358eV is observed in the spectra of the ZnO:N film after annealed in N2, this emission band is due to donor-bound exciton (D0X). After annealed in O2, the PL of the donor-bound exciton disappeared, an emission band located at 3.348eV is observed, this emission band is assigned to acceptor-bound exciton (A0X).
WANG Xiang-Hu;YAO Bin;WEI Zhi-Peng;SHEN De-Zhen;ZHANG Zhen-Zhong;LU You-Ming;ZHANG Ji-Ying;FAN Xi-Wu. Formation Mechanisms of Electrical Conductivity and Optical Properties of ZnO:N Film Produced by Annealing Treatment[J]. 中国物理快报, 2008, 25(8): 2993-2996.
WANG Xiang-Hu, YAO Bin, WEI Zhi-Peng, SHEN De-Zhen, ZHANG Zhen-Zhong, LU You-Ming, ZHANG Ji-Ying, FAN Xi-Wu. Formation Mechanisms of Electrical Conductivity and Optical Properties of ZnO:N Film Produced by Annealing Treatment. Chin. Phys. Lett., 2008, 25(8): 2993-2996.
2008, Vol. 25 
